1. Field of the Invention
This invention relates to an endoscope in an endoscope cover system comprising an endoscope for a cover, an endoscope inserting channel through which this cover endoscope is inserted and a channel fitted endoscope cover provided with a fluid channel through which a fluid passes so that, at the time of the maximum curvature, a fluid tube path will be curved and twisted so as to move to the side on which the radius of curvature is larger.
2. Description of the Related Art
It is necessary in an endoscope inspection to use a clean endoscope washed and sterilized before the inspection. A repeatedly used type endoscope in which the inserted part is washed and sterilized before the use and a used and abandoned type endoscope cover system endoscope in which the inserted part is replaced after the inspection have been previously suggested.
As disclosed, for example, in U.S. Pat. No. 4,991,564, the endoscope cover system endoscope comprises a combination of an endoscope cover (briefly mentioned as a cover hereinafter) and an endoscope for an endoscope cover (briefly mentioned as a cover endoscope hereinafter) to be inserted into the endoscope cover.
Because the cover is abandoned after it is used, it is not required to have the same degree of durability as in the repeatedly used type endoscope. Thus, it may have a durability level sufficient for only one inspection and may be as inexpensive as possible.
Here, the cover most likely to be damaged is the cover part (mentioned as the inserted part cover part hereinafter) covering the inserted part to be inserted into the body of a patient.
A plurality of tube paths are provided within the inserted part cover part and are classified largely into the following two kinds.
One kind consists of thick walled tube paths such as endoscope inserting channels and fluid tube path housing channels. These tube paths are made of a comparatively soft bendable material. On the other hand, the other kind consists of thin walled tube paths such as air and water feeding and sucking tube paths within fluid tube path housing channels. These tube paths must have smooth surfaces for fluids to pass through them. A comparatively hard material is used to make them.
These tube paths are curved and bent with the curvature of the cover endoscope inserted through the endoscope inserting channels.
The problem in the case where the tube path is bent is that the radius of curvature-of the part inside the bend will become so small that the tube path will buckle.
It is when the curvature angle of the cover endoscope is at a maximum that the radius of curvature inside the bend will become smallest. Particularly, the air and water feeding and sucking tube paths which are low in the durability to the bend and are hard and thin in the wall will be likely to buckle. Also, when the bending is repeated, the buckle will likely recur.
When these tube paths buckle, the wrinkles generated within the tube paths will tend to cause an obstruction of the flow of the fluid and the inspection will be interrupted.
In order to solve this problem, it is necessary to use a tube path material which will not buckle even at the time of the maximum curvature of the cover type endoscope.
However, with this method, the durability can be secured even in the direction in which the maximum curvature angle is not generated and it will be safe but with greater quality than necessary and it.degree. will be difficult to provide the cover cheaply.